<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html" charset="utf-8">
    <title id="title">Title</title>
</head>
<script language="JavaScript">
       function sum_alert(n1, n2){
            alert(n1 + n2);
       }

       function sum_confirm(n1, n2){
            confirm("sum = " + (n1+n2) + " ?");
<!--            var b = confirm("sum = " + (n1+n2) + " ?");-->
<!--            alert("your choice is "+b);-->
       }

       function sum_prompt(n1, n2){
            prompt("sum?" , (n1+n2))
<!--           var b = prompt("sum?" , (n1+n2));-->
<!--           alert("your input is "+b);-->
       }
</script>
<body>
<h1> JS invoke Java </h1>
</body>
</html>